The following description of the background of the invention is provided to aid in understanding the invention, but is not admitted to describe or constitute prior art to the invention.
The invention relates in part to a component for the attachment of a sole to an upper to form an article of footwear.
Footwear generally consists of a flexible open bag (known as an upper) for fixing about the foot of a wearer, and a sole attached below the upper. The sole may include an element designed to attenuate shock, generally referred to as a midsole. The sole may also include an element designed for ground engagement, generally referred to as an outsole.
Several methods of attaching an upper to a sole have been developed. In slip lasting, force lasting or tubular construction, a upper is generally extended below the feather edge of the last and stitched to itself to form a bag. In this construction, no lasting board is present. In California slip lasting a lasting board, sometimes called a slip-sock, is stitched to the edges of the upper below the feather edge of the last. The upper is held in shape about the last while a sole is attached.
In string lasting, the upper is drawn about a last by pulling two strings stitched to the lower margin of the upper. The action of gathering the lower margin of the upper below the featherline is followed by the application of a sole to maintain the shoe shape prior to removal of the last. A lasting board is rarely used in this construction. When present, it is used as a rigidity--providing sheet element lying inside the feather edges of the last.
In flat lasting, a lasting board is placed along some portion of the bottom of the last inside the feather edges. The upper is drawn over the last and the lower margin wrapped onto the lasting board where it is secured with cement, stitching, staples, nails, tacks or rivets. A sole is attached to the upper and the last removed.
Moccasin construction uses a lasting board, sometimes called a shankboard, in the heel area inside the feather edges of the last with upper material wrapped under the forefoot. As in other methods, a sole is attached by cementing, stitching, direct injection, vulcanizing, molding or nailing before the last is removed. Rib lasting, flange lasting and Goodyear welt lasting all involve attaching the upper to a flat rigid welt board for attachment to a sole unit usually by cement, stitching or stapling.
These methods of using lasting boards to attach sole and upper elements are shown in art on footwear, for example, Whatley U.S. Pat. No. DES. 309,055 shows a shoe constructed by flat lasting with cement. Several variations on these constructions are taught by the following art.
Conroy U.S. Pat. No. 3,854,228 discloses an inflatable footwear component which includes a linking tube that passes below the last during shoe construction.
Devlin U.S. Pat. No. 4,107,857 discloses a shoe construction in which upper straps are wrapped below a lasting board for attachment.
Fukuoka U.S. Pat. No. 4,150,455 discloses a method for manufacturing footwear in which sole elements are directly injected onto uppers with or without lasting boards present.
Hockerson U.S. Pat. No. 4,322,895 discloses a method of wrapping a foam midsole onto the upper above the feather edge.
Misevich U.S. Pat. No. 4,542,598 discloses a shoe with two separate sole units attached to an upper with a lasting board.
Meyers U.S. Pat. No. 4,627,177 discloses an insert to be placed in a shoe above the lasting board.
Richard U.S. Pat. No. 4,736,531 discloses a shoe construction in which an elastic upper element is wrapped below a lasting board.
Misevich U.S. Pat. No. 4,854,057 discloses a board for inclusion within a sole to alter the torsional rigidity of the shoe.
Robinson U.S. Pat. No. 4,922,630 discloses an ankle support strap for attachment by wrapping below a lasting board or attachment to an upper.
Spademan U.S. Pat. No. 4,924,605 discloses a shock absorbing system which may be attached above or below a lasting board.
Fuerst U.S. Pat. No. 4,947,560 discloses a shoe construction in which a sole is wrapped onto the upper and secured with stitching.
Whatley U.S. Pat. No. 5,060,401 discloses a cushioning element which may be attached between the lasted upper and the sole unit with or without the presence of a lasting board.
The following publication and U.S. patents provide disclosure that aid the interpretation of the present invention: Rokahr, U.S. Pat. No. 1,286,787 (issued Dec. 3, 1918); Hurley, U.S. Pat. No. 1,602,675 (issued Oct. 14, 1922); Eddins, U.S. Pat. No. 1,637,897 (issued Aug. 2, 1927); Cutillo, U.S. Pat. No. 2,070,116 (issued Feb. 9, 1937); Glidden, U.S. Pat. No. 2,147,197 (issued Feb. 14, 1939); Williamee, U.S. Pat. No. 2,850,813 (issued Sep. 9, 1958); Danowsky, U.S. Pat. No. 3,323,232 (issued Jun. 6, 1967); Conway, U.S. Pat. No. 3,464,125 (issued Sep. 2, 1969); Vaccari, U.S. Pat. No. 4,132,016 (issued Jan. 2, 1979); Salomon, U.S. Pat. No. 4,253,251 (issued Mar. 3, 1981); Schmohl, U.S. Pat. No. 4,342,161 (issued Aug. 3, 1982); Gamm, U.S. Pat. No. 4,550,511 (issued Nov. 5, 1985); Tanzi, U.S. Pat. No. 4,706,316 (issued Nov. 17, 1987); Caberlotto, U.S. Pat. No. 5,339,544 (issued Aug. 23, 1994); and Segel et al., U.S. Pat. No. 5,323,549 (issued Jun. 28, 1994).